Announcement

Collapse
No announcement yet.

Gap Difference on Point-gctid404843

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Gap Difference on Point-gctid404843

    My boat has been running good up until i went to florida then came back and all of a sudden, starting having some problems!! why is that. You go away come back and something is wrong!!! LOL, I had hard time starting her up. Took awhile but eventually got it going. Started right up after shutting her down t least twenty times. thn the next night would start until i changed the point, it was burnt pretty good.

    Check all visual items.

    getting fuel into carb

    fuel pump is good

    i changed water separator

    changed gas filter

    changed oil and filter

    c hanged spark plugs. they were bad!

    i also changed the point, but i gapped it to big. suppose to be at 16, for some reason i gapped it 27. i think the plugs are 27. a also have to change the condensor as well and then time it.

    when i took her out for a run, I basically had no power. maybe 3000 rpms if lucky. you could feel there was no kick at all just slow motion!!

    would the large difference in gap cause the loss of power.

    also i have a slow aiR leak coming from the manifold gasket. i covered it with plumbers putty until i can pull it off and replace the gaskets. would this cause a loss of power as wells?

    trying to get by this year because I have almost a brand new engine i bought. baby is spanking clean and not a thing wrong with it. going to install it next yeAR!!

    THANKS

    #2
    Incorrect gap can cause power issues. Set gap correctly,or better yet replace points;then you will need to retime engine of course. Man. leak not good either, try points first.

    Comment


      #3
      Setting contact point gap is an estimate only of correct dwell angle.

      Your Volvo Penta AQ125A distributor rotation has 90* in which to make/break contact for one cylinder.

      Dwell Angle will be a portion of this 90*.

      Use a dwell meter to set the correct dwell angle.

      Check your progressive spark advance as well as the full in advance. The OEM manual will give you this info.

      Yes, a vacuum leak at the intake manifold will hurt performance.
      Rick E. Gresham, Oregon
      2850 Bounty Sedan Flybridge model
      Twin 280 HP 5.7's w/ Closed Cooling
      Volvo Penta DuoProp Drives
      Kohler 4 CZ Gen Set

      Comment


        #4
        I chaged the condensor tonight and re-gapped the point to 016 mm. The correct size. Time it at 10 degrees btdc!. Started up and but still seemd alittled rough kinda. when i was at the dock i didnt use the dwell meter, i figure i go out for a run and see. Still had n power, i onlt got uo to 3500 rpm, which normally i get when im alone about 4600-4800!! i figure i would maybe play around with the timing again and adjust it.Then when i shut her down, she did not start up again, just cranking. Sdemed lik it had no life to it when cranking! WTF. I had to call BOAT US FOR A TOW AT 1AM IN TH MORNING!!! right now im about to take it out and b done with it for this year! im agrevated and fustrated. Put the top on and call it a year. Im going to replace the engine next year. The one i have is in perfect running condition!

        [img]/media/kunena/attachments/vb/708706=30159-volvopenta1.jpg[/img] Attached files [img]/media/kunena/attachments/vb/708706=30161-volvopenta2.jpg[/img] [img]/media/kunena/attachments/vb/708706=30160-volvopenta3.jpg[/img]

        Comment


          #5
          jmess69

          2850Bounty wrote:
          Setting contact point gap is an estimate only of correct dwell angle.

          Check your progressive spark advance as well as the full in advance. The OEM manual will give you this info.
          Your dwell angle can/may be perfect, but unless the progressive advance is functioning, you won't get any performance out of it.

          Look for rusty flyweights and/or rusty flyweight return springs.

          Strobe your timing marks @ idle and @ the various RPM up to the limit RPM.

          See your Volvo Penta OEM specs.
          Rick E. Gresham, Oregon
          2850 Bounty Sedan Flybridge model
          Twin 280 HP 5.7's w/ Closed Cooling
          Volvo Penta DuoProp Drives
          Kohler 4 CZ Gen Set

          Comment


            #6
            It is easy to see if your advance is working right. Have the engine at idle with the timing light on. Now bump the rpm up and see if the timing advances progressively.

            These distributors have two small springs in the bottom of the dizzy underneath the points. If you figure how old they are and what they are made off I am not surprised if all of them are on their last legs or already broken.

            Trying to run at speed with retarded ignition would be exactly the conditions you describe. It would also be intermittant because the dizzy would move around all the time and who knows where it was sitting when you set the timing. The range is considerable.

            I had broken springs. I have first hand experience. I wouldn't give up on an engine because of what appears to be a tune up issue.

            Comment


              #7
              th reason why it didnt start was because the electrical clip that goes to the condensor was not attached to it, it must have slipped off and i didnt realize when i shut it don, that's why it didn't start. but i had no power!

              as soon as i hook it up, it started. I timed it again at 10 degrees, sounds great when idling, starts right up every time! I check spark in each cylnder and thats good! i did a compression test on each one. and it wasnt good!

              cylinder

              1-90

              3-100

              4-130

              2- 120

              I took her out and still no power, i only went up to 3800 rpm,on my new engine i bought, when i checked the compression on that each one was exactly 150. that's a huge diffrence!!

              loss of compression would cause the loss of power?

              I did not check the weights and springs under the point like trophy said, i forgot to! but i will do it soon. Can the springs be causing the loss of power as well. but with those compression numbers?

              thanks

              joe

              Comment


                #8
                Joe, your fuel system, caburetor, compression, dwell angle, spark quality etc, can all be perfect..... but unless the engine sees the correct progressive advance, you will NOT get the performance from it..... period!

                This is why both Tony and myself have made this suggestion to you.

                All it requires is a bit of distributor water intrusion, rust/corrosion that follows, and before we know it, the flyweights quite functioning, and/or the flyweight return spring value deminishes due to rust.

                If the flyweights freeze up, we end up with a mechanical advancing system that is not advancing.... of which = no performance.

                If the flyweight spring value changes, we can end up with an overly aggressive advance.... of which = potential engine damage.

                I hate to see you just roll the dice here!

                Check this out before you damage something.
                Rick E. Gresham, Oregon
                2850 Bounty Sedan Flybridge model
                Twin 280 HP 5.7's w/ Closed Cooling
                Volvo Penta DuoProp Drives
                Kohler 4 CZ Gen Set

                Comment


                  #9
                  jmess69 wrote:


                  cylinder

                  1-90

                  3-100

                  4-130

                  2- 120
                  I'm not following you on the "new engine" thing..., or why the order above is 1,3,4,2, but charge the battery fully, remove all 4 spark plugs, open the throttle full and recheck your compression

                  if you started at 4 and saw compression numbers in this order, 130,120,100,90... it makes me think your battery was dying during the test

                  or if it was 90,100,120,130... that looks like it improved with each sequential plug removal which gets the engine spinning faster

                  Comment


                    #10
                    I went to the volvo dealer the other day . and he does not have any of the weights in springs , he said he cant get them anymore. I have to check the schematic and see the parts. do you know where else I can get them from ? so what you're saying is if I keep running the engine like this I could doore damage?

                    Comment


                      #11
                      First thing to do is check to see if you need new springs. If the advance is working properly and it is not all rusty down there, you are fine.

                      If you do need them replaced they are not available anywhere. I searched all of the internet. Checked for old stock with dealers and emailed Volvo car performance guys. Even though the dizzy is a Bosch, they won't match.

                      You will have to buy a good used one on Ebay or Craigslist.

                      On Ebay the going rate is about $150 which is quite a bit better than the list price of a distributor which is $1,500

                      I ended up finding mine 15 miles away on Craigslist for $50 and it is in great shape and has been working perfect.

                      BUT, first check if you need it. Visually inspect the mechanism and check to see the timing advance with the timing light. It is less work than your compression test.

                      Comment


                        #12
                        whywhyzed wrote:
                        if you started at 4 and saw compression numbers in this order, 130,120,100,90... it makes me think your battery was dying during the test
                        ........ or, he's not cycling each cylinder at least four times (i.e., 8 crankshaft revolutions).

                        jmess69 wrote:
                        I went to the volvo dealer the other day . and he does not have any of the weights in springs , he said he cant get them anymore. I have to check the schematic and see the parts. do you know where else I can get them from ? so what you're saying is if I keep running the engine like this I could doore damage?
                        Joe, I doubt that you need new flyweights. The weight, cam area, nor the hinge point changes, so these can almost always be cleaned up, lubed, and re-used.

                        It's the springs that are tricky to replace! Not that they're hard to find, it's getting the correct spring value that will offer the correct curve.

                        This is a very sensitive part of the mechanical advancing system, and quite honestly, best if done by a professional and with the aid of a distributor machine.

                        .
                        Rick E. Gresham, Oregon
                        2850 Bounty Sedan Flybridge model
                        Twin 280 HP 5.7's w/ Closed Cooling
                        Volvo Penta DuoProp Drives
                        Kohler 4 CZ Gen Set

                        Comment


                          #13
                          Actually Rick, the size of the springs is so odd, even other Bosch springs aren't the right length.

                          Comment


                            #14
                            trophyboat wrote:
                            Actually Rick, the size of the springs is so odd, even other Bosch springs aren't the right length.
                            Correct! The two return springs are never of the same spring value.

                            What I should have said, is that return springs, in kit form, are generally available, and in the right hands, can be made to work by tweaking, testing, and adjusting until the curve is correct.

                            The key to this, is in "the right hands"..... as in a shop who owns/operates a distributor machine, and with a Tech who has the specs right there in front of him.

                            Otherwise, it's a crap shoot, unless you know how to test "On Engine".

                            Like said; a non-agressive spark advance will cause poor performance..... an agressive spark advance may cause engine damage.

                            We need to be as close to OEM specs as we can be.

                            .
                            Rick E. Gresham, Oregon
                            2850 Bounty Sedan Flybridge model
                            Twin 280 HP 5.7's w/ Closed Cooling
                            Volvo Penta DuoProp Drives
                            Kohler 4 CZ Gen Set

                            Comment


                              #15
                              When I say new engine. I'm referring tovthe engine I bought at the beginning of the summer. I'm going to install it next year. I'm trying just to get by this year without spending too much$$$$ oon thia engine.

                              I'm thinking what if I took off the distributer fdon the engine I have sitting and install it on the one that's in the boat. And then next year just swap it back out. Would that be easier?

                              Comment

                              Working...
                              X